1. Field of the Invention
The present invention relates to a portable communication apparatus such as a portable telephone, and more particularly, to a portable communication apparatus having a slide-type structure provided with unprecedented functions to improve the convenience in use.
2. Description of the Related Art
In recent years, the portable telephone set has become to be used not only just for speech communication, but also as a portable information terminal having additional functions such as a browser for the Internet or the like, an E-mail transmission/reception and schedule control. Accordingly, since the contents to be displayed include a lot of character information, images and the like, it is desired that the display device is large in size.
In addition to a straight-type portable telephone apparatus, foldable or slidable structures have been employed to meet the needs for miniaturization. The foldable or slidable structure is very suitable for installation of a large-sized display device. In a foldable portable telephone, the display device is mounted in general such that, when folded and not used, its display faces inside to be protected. Some foldable portable telephones are provided with a secondary display device on its back surface so as to display minimum information even when folded.
The slidable structure is provided with a main housing (first unit) and a movable housing (second unit), which is mounted with a part of functions and is coupled with the main housing so as to be slidable in the longitudinal direction. Such a structure allows the two units to be retracted with overlapping one another when carried and to be extended by sliding them in the longitudinal direction when communicating or the like. Many slidable portable telephones are designed such that, when folded and not used, its display faces inside to be protected.
For example, Japanese Unexamined Patent Application Publication No. 7-312631 discloses a portable radio apparatus, which comprises a first housing having at least a receiver and a display section, and a second housing, which is accommodated within the first housing so as to be freely slidable and rotatable with respect to the first housing and is provided with an operation section and a transmitter on the front surface thereof. By sliding and rotating the second housing to be accommodated into the first housing, two states are realized: a state that operation and speech communication are available; and a state that the operation face is protected with facing in.
Also, Japanese Unexamined Patent Application Publication No. 5-91015 discloses a small-size portable radio apparatus, which comprises a housing that has a transmitter, a key operation section and a display section and has a recess portion formed extending in the longitudinal direction, and a movable housing that is equipped with a receiver and incorporated into the recess portion so as to be freely slidable. When being out of use, the movable housing can be inserted into the recess portion to compact the entire; and the movable housing can be pulled out to a desired length to be used for speed communication. When the movable housing is inserted into the recess portion to compact the entire, the display section of the housing is partly exposed, allowing the time of day or the like to be displayed thereon. On the other hand, when the movable housing is pulled out, almost all the display section is exposed, allowing the increased amount of information to be displayed thereon.
Further, in Japanese Unexamined Patent Application Publication No. 2001-24762, a portable telephone apparatus is composed of a main body thereof having a display section provided on one side thereof, and a keypad having operation buttons provided on its surface, which is slidable to cover the display section of the main body therewith. When the main body accommodates the keypad, a part of the display section is exposed from the keypad. When the keypad is slid downward, the entire screen of the display section is exposed. The keypad slides up and down along guide rails provided at both right and left sides of the main body. In the portable telephone apparatus, it is possible to enlarge the displayable screen without injuring the portability and the operability to achieve the displaying of a large amount of information such as mail and data. In the accommodation state, information necessary for audio communication is displayed, and by exposing the entire screen, it is possible to read character information such as mail.
In those conventional portable telephone apparatuses, it is necessary to slide two portions into an extended state using both hands to carry out speech communication, resulting in room for improvement of the convenience in use.
Further, a portable telephone having an optical function has been also provided according to the trend of multi-function and high performance. For example, it is mounted with an electronic camera for capturing image data. Furthermore, a portable telephone mounted with a fingerprint recognition system has been provided so that only authorized users can operate the portable telephone itself or identification of a caller can be verified. Such an optical function has an optical aperture section exposed to the outside and any dirt or flaw may prevent it from functioning normally.